Re: [PATCH v3] drm/i915: Optimistically spin for the request completion

Chris Wilson
2015-03-12T16:50:22Z

On Thu, Mar 12, 2015 at 04:41:10PM +0000, Tvrtko Ursulin wrote:
> Yes I didn't mean that - but to have a boolean spinning-wait=on/off.
> Maybe default to "on" on HZ=1000 with preemption, or the opposite,
> something like that.

I don't see the point in having the complication, until someone
complains. In my defense, I will point to the optimistic mutex spinning
equally having no configurable option. And since the idea is that you
only hit this if you are abusing i915 (e.g. benchmarking, or you have a
readback on the critical patch, or if we haven't implemented
semaphores), I would rather fix those scenarios as they arrive rather
than giving the user an option to break.
-Chris

--
Chris Wilson, Intel Open Source Technology Centre